Question

Parents that are heterozygous for having freckles (dominant) are crossed.

What represents the ratio of their offspring? Draw a Punnett square and show your work.

Answer 1

Phenotypic ratio - 3 Freckes : 1 No freckles

Step-by-step explanation:

This question represents a monohybrid cross i.e. involving a single gene coding for possession or not of freckles. The allele for possession of freckles (F) is dominant over the allele for no freckles (f).

In a cross between two HETEROZYGOUS parents i.e. Ff × Ff, each parent will produce gametes with alleles F and f respectively. Using a punnet square (see attached image), four possible offsprings will be produced with genotypes: FF, Ff, Ff and ff.

Based on this genotypes, the phenotypic ratio of the offsprings will be 3:1 where 3 offsprings will possess freckles and 1 will have no freckles.